* Judge imposes maximum prison term allowed

* Cheers and applause from courtroom spectators

* Madoff says he has left a "legacy of shame"

* Ruth Madoff says she feels betrayed by husband's crimes

* White House says sentence sends strong signal (Adds comment from White House, law professor)

By Grant McCool and Martha Graybow

NEW YORK, June 29 (Reuters) - Bernard Madoff was sentenced on Monday to 150 years in prison -- the maximum penalty the judge could give him for "extraordinarily evil" crimes in Wall Street's biggest and most brazen investment fraud.

Fleeced investors in the courtroom cheered and applauded as the judge handed down the penalty.

Madoff, 71, stood passively with his hands clasped at his waist, showing no reaction when he heard the sentence that will send him to prison for the rest of his life.